Flying shear



June 21, 1938. Q FISK 2,121,145

FLYING SHEAR Filed Feb. 8, 1956 6 Sheets-Sheet l June 21, 193s. Q L, HSK 2,121,145

FLYING SHEAR Filed Feb. 8. 1936 6 Sheets-Sheet 2 l n@ [Wl l M d I PWA June 2l, 1938. G, FISK 2,121,145

FLYING SHEAR Filed Feb. 8, 1956 6 Sheets-Sheet 3 Mme 2L 1938. G. L. FISK ZZLM FLYING SHEAR n Filed Feb. 8, 19556 6 Sheets-Sheet 4 .Fume 2L 1193. G. L. FlsK FLYING SHEAR Filed Feb. e, 1956 6 Sheets-Sheet 5 G. L. HSK ZJZLMS FLYING SHEAR Filed Feb. 8, 1936 6SheebS-Sheet 6 refereed imei, 193s Um'rEDsTATEs PATENT ori-ICE FLYING SHEA!! Gustar L. Fisk, New YorkfN. Y.4 Application February 8, 1936,` Serial No.162,910 21 claims. (o1. lei-es) The present invention relates to a flying shear for shearing to comercial lengths travelling strip material or istocky that usually may comprise sheet, iiat or bar strip delivered to the shear from rolls in a steel rolling mill.

A purpose of the invention is simultaneously to rotate and in the plane of rotation angularly to oscillate the driving member of a rotary shear.

A further purpose is to oscillate on their own axes the cooperating knife members of a rotary shear and adjustably to determine the peripheral speed of the cutting knives at the moment Vgf cutting by a phase adjustment of the oscillaion.

A further purpose-is to relate the position of av cyclic phase adjustment member for a rotary shear to the length of pieces to be cut successively by the shear.

A further purpose is to drive a rotary shear by cyclic connections, suitably crank and connecting rod connections, to planetary gears and angularly toadiust a normally stationary sun gear meshing with the planetary gears inorder M; adjustably to determine the peripheral speeds oi the shear knives at the instant oi cutting.

A further purpose is to provide a cycle of variant speeds of rotation of the shears oi a rotary dying shear and to cut selectively at varia@ ant parts of this cycle so as to secure, for any given rate of rotation oi the driving motors, knife speed corresponding to the part of the cycle selected.

A further purpose is to connect a planet gear revolving around a sun gear which is xed during action with a rotary member of a rotary cutter train. through cyclic speed changing mechanism and to angularly shift the sun gear to a new fixed position to secure a speed of ro- 40 tation at cutting position corresponding to a new part of the speed changing cycle. 1 A further purpose is to provide a variant cycle of rotary iiying shear cutting blade speed and to adjust the cycle with respect to the cutting 4g position of the shear knives, whereby the speed of cutting is the same when set and corresponds with the speed at the point in the cycledetermined by the adjustment.

A further purpose is to provide a cycle of ro- 50 tary iiying shear knife speeds the same for the same main driving speed, but differing, while of ithe .same character, for different driving speeds and to adjust the angular relation of the parts of the cycle to the cutting position in order to 55 cut at any of the variant speeds within the cycle.

A further purpose is to drive rotary cutting knives of a ilying shear through planets and an. adjustable sun gear which is xed in'operation 0 and to turn the sun gear to vary the angular relation between the cutting polntand the cycle of knife speeds produced.

A further purpose is to connect the driving mechanism of rotary ilying shear cutters with 'the cutters through cranks and planets about a sun gear whereby the interposed crank operation causes a regular and characteristic cycle oi speed variation successively adding to and taking from the speed of the planet rotor, adjusting the angular positions at which these cyclic additions and reductions takeplace withrespect to the cutting knives.

Further purposes willv appear in the specication and in the claims.

The invention relates not only to the methods or processes involved but to` mechanisms by 'which the methods or processes may be carried forms of my invention, showing however detail variations and selecting a main form and variations thereof that are practical and efficient in operation and which wellv illustratethe princiy ples involved.

Figure l is a top plan view, with cover removed showing structure embodying a desirable form of my invention.

Figures 2, 3 and 4 are vertical sections of Figure l taken respectively upon the line 2 2, 3-3 and i--t thereof.

Figure 2a is a fragment of Figure 2 modified to show an indicator for the length of out.

Figure 2b is a fragmentary front elevation oi? Figure 2a.

Figure 53is a section. upon line 5-5 of Figure 3.

Figures 6 and 'l are diagrammatic views showing the eiects of angular adjustment of the sun'and planet positions in varying peripheral speeds at the shear knives during the instants of cutting the strip.

Figure 8 is a diagrammatic view showing the relations of crank positions at dilerent intervals of movement of the planetary crank-operating gears about the sun gear.

Figures 9, 10 and 11 are fragmentary sections showing the effects of sun gear adjustment on crank gear and cutter position, with the sun and planetary gearing of Figures l to 4.

Figure l2 is a diagrammatic view of a shear support modification, showing one knife only on the lower knife support. l

Figures 13 and 14 are diagrammatic views showing modifications.

Like numerals refer to like parts in all figures.

Describing in illustration and not in limitation and referring to the drawings:

The ordinary rotary shear with knives revolving at bar speed cuts a length equal to the distance of travel by the bar between cuts. By inthat of the bar.

It has been proposed to alter the average length" oi' cut, at which the bar speed and knife speed are equal, as. obtained in this way, by superimposing an angular velocityupon the knives to reduce or increase the speed at the moment of .cutting to that of the bar. When this superimposition is not made the shear of course returns to cutting average lengths and operatesthe same as the ordinary rotary shear.

I give up whatever advantage there may be in setting for average length in the interest of simplicity of operation and design and provide a predetermined and fixed cyclic rate of speed fluctuation. at any given driving `motor speed. varying in frequency of course also in direct proportion to the speed of the driving motors. 'I'hls rate and extent of speed fluctuation are made sumciently large to cover the full range of requirement for any particular shear. Knowing a bar speed and the length of cut desired, the driving motor speed is set to give the required number of cutter turns in a given bar length and the knife position is adjusted so that the knives will cut at that selected part or phase of a regular cycle of knife speed change at which the knife speed and bar speed substantially coincide.

In the preferred form of the construction the cyclic speed change inserted between the constantly revolving planets and the cutting mechanism is in the form of a crank arm and connecting rod between each planet shaft and a rotary member of thecutting train. 'Ihis form', therefore will be described in detail.

As seen in Figures l to 5 upper and lower intergeared cooperating rotary shear knife supports I5 and i6 of usual or suitable construction carry knives I1 and I8 which areillustrated as cutting once in each full revolution of the upper knife and in every half revolution of the lower knife. Obviously the one to two ratio of the revolutions of these knives is selected for illustrative purposes and thisrelation as well as the number of cuts per rotation of the supports may be varied as desired. As in common practice, the knives travel in the direction of movement of the stock.

'I'he lower knife support is provided with bearing shafts I9 and 20 which turn in bearings 2| and 22 carried in the framestructure 23. Correspondingly the upper knife support is provided with shafts 24 and 25 which turn in bearings 26 and 21. 'Ihe respective shafts at one end carry intermeshing gears 28 and 29 which are here shown as keyed to the shafts 25 and 20.

'I'he shaft 20 is extended at 30 beyond the hub of the gear 28 to afford one bearing for the planet rotor 3| of a driving unit. The adjacent part of the unit comprises this rotor, planet gear or crank shafts 32 carried by the rotor and parallel to the main driving shaft, planet gears 33 one on each of the shafts 32, cranks 34 mounted one upon each of the shafts at the other end and connecting rods 35 by which crank pins 31 are joined to pins 36 in the larger shear gear 29.

The planet constructions are duplicates each performing the same function and each capable of acting entirely independently to transmit the motion, the plurality of connections being used to provide additional strength and to equalize the stresses about the shaft.

The pins at which the connecting rods terminate are shown in one of the connecting gears for the reason that they afford convenient rotating parts of the cutter train and in the larger of these gears because it is concentric with the sun. Obviously the pins can be placed in any rotating member which is convenient and which forms part of the cutter train.

'I'he extension 30 of shaft 2li is so close to the supporting bearing 22 of this shaft 20 within the frame as to afford support to the rotor at a bearing 39 and to a driving shaft 39 upon which the rotor is rigidly mounted. About the driving shaft v39 by bearings 40 and 40 is supported a sun gear 4I with which the respective planetary gears intermesh. In normal use this sun gear is fixed against rotation.

'I'he hub 43 of the sun gear carries a worm gear or segment 44 or 44' through which the sun gear may be adjusted angularly by a worm 45 whose shaft 46 is suitably journaled in any convenient frame parts. The worm 45l may be turned in either direction by hand operation of an adjusting wheel 4l upon the shaft 46 whereby the sun gear is shifted angularly with corresponding rotation of the planetary gears and revolution of the cranks carried by their shafts.

'I'he outer end of the driving shaft 39 passes through a suitable bearing 48 and a thrust bearing 49 is supplied for the purpose of protecting against longitudinal movement.

Beyond the bearing 48 the shaft 39 is splined to a gear 50 which in the illustration is the center of a train of three gears 50, 5| and 52 because plural driving motors 53 and 53' are indicated, each provided with a brake 54 or 54' as well known to stop the shear when the current is cut oil'. Each motor drives through its gear 5i or 52 by shaft 55 or 56. The parts are suitably mounted and journaled.

'I'he shear gear 29 makes one complete rotation for every complete revolution of the planetary gear orgears about the sun gear, but during this complete revolution, with the parts in the proportions shown, there are two complete cycles of variant speeds. During half of a rotation of each of the planetary gears about its own axis the crank shaft increases the speed of the cutter gear 29 as compared with the bodily movement of the planetary gear or gears in its or their revolutions about the sun gear and during the other half the crank shaft relatively reduces the speed. This gives a cyclic speed variation between each planet and the cutter train. Correspondingly there is a succession of increasing and decreasing cutter rotations and of knife movement which gives opportunity to select the particular speed at which the cutting is to take place and to adjust to secure the exact speed desired within the range of adjustment so that the speed of the knives at the time of cutting shall correspond with the speed of the stock.

The successive increases and reductions in speed of the gear 29 with respect to the bodily speed of the planet gears about the sun gear may be considered to be due to simultaneous rotation and cyclic motion (angular oscillation) and the extents of these increases and reductions of speed will depend of course upon the lengths of the crank arms with respect to the radii of the planetary gears as well as upon the radii (upon shear gear 29) at which the pins upon shear gear 29 are located. The lengths of the connecting rods will also affect the values of the several speeds because they will affctft/he angles at which the crank arms operate and at which the connection rods push or pull against the pins in gear 29.

The different relations and dimensions of the ,parts are as tools in the hands of the designer by which to suit the invention particularly to the needs of individual users to give prominence to features of the invention preferred by him.

'I'he entire mechanism is enclosed within anyl usual or suitable casing.

In Figure 2a is shown an indicator for the adiustment of a sun gear. 'I'he hub 62 is used as a drum for 'a cord 63 passing about pulley 64 and held in extended position by weight 63. The cord 63 carries a pointer 65 which indicatesupon a scale 6B preferably marked in feet or centimeters of length of cut. The rheostat or other controller 51 for the cutters will also preferably be scaled in feet of length of cut so that both the speed and the setting of the knives to correspond with the speed may be determined in length of cut without need of computation.

We can approach the determination of the driving speed `and corresponding surface speed of the knives to agree with the speed of stock from either of two standpoints. From the one standpoint shown in Figure 6 a curve having polar coordinates is plotted so that the distances at which any radii such as 58 strike thecurve at diderent angles about the center represent the comparative speeds through space of the knives at cutting positions for different angular adjustments of the sun, giving corresponding different initial angular positions of the cranks which revolve with the planets.

The speed of travel of the larger cutter gear divided by the R. P. M. of the motors will yield a constant curve for the same proportions of the parts.

In the illustration sun settings for maximum speeds are shown at 59, 59', for minimum speeds at 60 and 80' and intermediate speeds at 6|, 6|', SI2 and 6|?. The knives travel in the same direction as the stock.

With rotation as indicated by the arrow in Figure 6 it is desirable to make the cut with a sun setting corresponding to a position 6i or E l2 rather than to positions 6i or Bia, because at the settings 6i and BIz the knife speed is increasing at the time of cutting and the cutting knives will thus tend to push the cut stock away from the uncut stock rather than to drag against the uncut stock.

It is desirable to use cutter connections (number of turns per cut or parts of a turn per cut) such thatit will not be necessary to use all of the range of curve shown to cut commercial sizes and so that selection of speeds may be made in those portions of the curves which are well spaced both from the minimum and from the maximum shear speeds; from the minimum because of the wide range of adjustment with slight angular change of position with consequent opportunity for error and from the maximum because of the very slight changes in speed for a given angular adjustment.

It is preferred that the angular positions be secured by angular shifting of the sun gear but it is recognized that other adjustment means may be provided such for example as by disengaging the teeth of the planet from the sun and resetting in another angular position of the planet with respect to an immovable sun.

In Figure 6 it should be noted that there are two cutting positions for each complete rotation of the gear 29.

It will be obvious that my invention will operate with any relation between the faces of thecooperating cutter supports whether or not the knives register with each rotation of one or the other or both cutters.

From the curve in Figure 6 vthe requisite amount of adjustment of the planet with respect to the fixed sun position may readily be determined.

'I'he other method of approach is through the phase adjustments required for different lengths of stock cut and is conveniently approached mathematically notwithstanding that it is shown also empirically by the diagram in Figure 7. The mathematics for this determination follows.

If S=speed ln feet per minute of stock or strip material as it reaches the shear.

l=length in feet of the cut pieces.

N :revolutions per minute of large cutter.

n=speed of the driving motors.

D=diameter in feet of large knife.

:cuts of larger cutter per revolutionindicated as two in Figures 1 to 5, f Y=a phase of oscillation factor adjustable b adjustment of the sun wheel M at the hand wheel 4l'.

The speed S of the stock as it reaches the shear and the length l into which the travelling stock is to be cut by the flying shear are both outside the control of the shear operator, being for example respectively a constant of the mill, or of pick-up and delivery rolls thereof, and commercial lengths specified by customers. i

The shear operator, to cut the stock to length Z, initially adjusts the speed n of the motors 53 and 53' for S/l cuts per minute, that is, in effect adjusts the cuts per minute, Na, to a value S/l.

This speed adjustment of Na to equal S/I may be effected and may also be indicated by well known mechanisms shown conventionally at 51.

Having thus adjusted the revolutions per minute of the shear to the specified length! of cut, the operator next makes an accommodating adjustment at the hand wheel 41, turning the sun wheel to make the peripheral speed of the knife at the instant of cutting substantially equal to tge speed S at which the stock is reaching the s ear.

The operators rst adjustment makes Na-:S/l and his second adjustment makes the knife speed vrDNY equal to the speed S with whichl the stock is reaching the shear and does this by a right selection of Y, the phase factor. 1

Y is the continuously changing instant ratiov of the angular velocity of the shear gear 29 to that of the center driving gear 5|) and may be determined on the drawing board or elsewhere, for every angular position of the driving gear 56, being numerically equal, at any angular position of the wheel 5|), to the angular shift of the shear gear 29 for one degree shift of the driving wheel 50.

Since Szrmvy and =Na combining :irlDlilYmEl I I and I a Yn rrDY In the illustration the number o! complete cutting movements oi the shears for each rotation oi' the lower shear member and of the wheel Il is the same as the number of complete speed cycles for one complete revolution of the planet gears about the sun gear. In Figures 1 6 there are two cuts per complete revolution of the planet gears about the sun gear.

From the above a scale is obtained relating l, the length oi' the piece, and thelangular setting of the sun wheel-as in Figure 7 in curve 51.. As will there be seen, there are two complete cycles o! speed variation in'which the value oi Y oscillates through a wide range which is indicated as starting above zero and which with longer radii oi the crank arm may dip below zero. The extreme lower part of the curve would preferably not be used. In this curve 61 the ordinates represent lengths oi cut stock orstrip in any suitable unit such as feet and the abscissae represent angles of adjustment of the position of the sun with respect to stationary objects. It will be noted that the initialposition locates the length of cut as a maximum and that an entire range of adjustment from the maximum to minimum on one side or the other occurs within 909.

Whatever the speed ratio of the two cutter supports for the number of cuts per turn of the lower lcutter support it will be obvious that there is one complete rotation oi cutter gear 29 for each complete yrevolution of the planets about the sun.

Figures 6 and 7 may equally represent a speed cycle of the knife members for one turn of the rotor ll, that is the Iperipheral speed of the knives at each angular position of the rotor; or, as already explained the speeds of the knife at its cutting position for different settings of the sun gear (Figure 6) or the proper settings of the sun wheel for diiIerent lengths oi cut (Figure 7).

In the curve 51 maximum values are indicated at 5I and 59 andrminimum values at 10 and 1I.

In Figures l-S and in the curves in Figure 6 and `at 1I in Figure 7 a lower cutter support twice the size of the upper cutter support has been contemplated whereas in curves 12 and 12' of Figure 7 .the upper and lower cutter supports have been assumed to be of equal diameter or that a single cutter only is used on the lower cutter support of Figures 1-5. Curve 61 would apply in such a situation with one point of cutting only for the two cycles but the curve is unnecessarily steep for such an intended use and it is better to have a single cycle only throughout the 360. This is secured as seen in curves 12 and 12' (Figure 7) by assuming that the sun and planets are of equal diameter.

Where the sun and planets are of equal diameter with the same crank arm lengths the'range of difference in speeds throughout the cycle will be considerably reduced as seen in curve 12. If a range of speeds corresponding or nearly corresponding to that of curve 51 be desired it can be secured by increasing the lengths of the cranks carried by the planetfgears or by reducing the diameter of the pin circle at which the rods 35 are connected to the gear 29. 'I'he longer crank arm distinguishes curve 12 from the shorter crank arm curve 12.

In connection with Figure 8 it should be pointed out that the sun and planets there indicated lie in fact between the observer and the crank arms 34, rods 35, pins 35 and gear 29 to which the pins 35 are connected.

In Figure 8 crank arm and connecting rod positions are shown diagrammatically at intervals curve).

-tion of whether the advantage of the higher range im throughout the entire circumference to show the successive increments of advance and retardation due to the crank. 'I'he several positions .are shown at 13 to 84.

In position 18 the crank is shown at lapproximately maximum eilective throw in increasing the speed of the cutters. In position 14 the assistance oi .the crank reduces until at 15 the crank has no eiIect in increasing but instead reduces the speed which the cutters would have if driven directly from the planet gear.

At 15 the operation oi' the crank is still reducing the movement of the cutters which would otherwise be due to revolution oi.' the planets. With the proportions shown the cutters have vapproximately stopped and may even have reversed in direction between position 15 and position 15. 1f the crank arm be extended in positions 15 and 15 to indicate the crank arm slightly exceeding the radius of the pitch circle of the planet gears, it will be evident that the curve will deilnitely go below the zero and reverse the direction of the cutters. In order to take care of both situations, where the proportions are such that the crank does not reverse Ythe direction of knife movement, and also the proportions in which thek crank does reverse the direction of movement of the knife, the zero point has been left out in Figure 7, indicating the character of the curve without intending to limit either to dipping of the curve below the zero point or having the node above the zero point. There may be an advantage in dipping the curve below the zero point (i. e. having the cutter momentarily reverse in movement because this lower dipping of the curve will mean a corresponding higher reach of the upper range of the 'I'his must be measured upony the quesabove to be reached justifies reversing movement of the cutter since the dipping of the curve below the zero point means a steeper curve and less sensitiveness in setting to denite commercial lengths.

Between the position 16 and the position 11 the crank continues to hold the instantaneous speed of the cutter down nearly to zero, that is, there is very slow movement or with a longer crank definitely a backward movement of the cutters. Between positions 11 and 18 the crank arm is assisting in the forward movement of the cutters which increase in speed rapidly'to a maximum between 18 and 19. The curve is repeated through positions 8|), 8|, 82, 83 and back to position 13.

The illustration in Figure 8 clears up the reasons for the dips, high spots and steepness of parts of the curve in each of Figures 6 and 7 and emphasizes the fact previously `mentioned that the character of contour of the cyclic movement secured between the planet gear and the cutter train is within the control of the designer using the proportions of sun to planet, crank arm length and ratio of crank arm length to planet diameter, the connecting rod length and the diameter of the crank position at which pin connection of the connecting rod with the rotatable member of the cutter train (here gear 29) takes place.

In Figures 9, 10 and 1l appear three different positions of the sun gear with three correspondingly -diierent relations between the crank angle and the cutting point.

In Figure 10 the sun 4| and planet 33 are shown in `position with the crank 34 straight in line with the connecting ro d 35, pushing the cutter gear 29 far'in advance 'of the position to which it would be pushed if due alone to move- `tal worm gear E In Figures 9 and 11 new positions of the parts 4 I are shown due' toadjustment of the sun without corresponding bodily movement of the planet rotornor of the cutters yshowing nearly maxi- `mum increases Vin speed of the cutter gear with crank operation in Figure 9 and approximately a maximum reduction in speed with movement of till' the planet gear in Figure l0. Obviously the cyclic connections between the planet or planets and. a rotary member of the rotary cutter train need not be of crank and pitman type but may be of any of a great Variety of other types of which two gear forms are shown in Figures 13 and 14. 1

In Figure 13 the sun gear 4I and planet 33 are shown in engagement in central position with cutter supports I5 and I6 shown as a background and the knives in cutting position within a plane through the axes of the cutter shafts. `The'elliptical gear 85 is fixed to the planet shaft 32 and cooperating gear 86 is fixed to the shaft 2l)l so thatthe twoelliptical gears comprise a cyclic speed changing connection between the planet shaft and the cutter support shaft.` Under these circumstances the phase of the cyclic speed change can be varied by adjustment of the sun gear, or of the planet.

In Figure 14 the same kind of construction is found except that centrally pivoted dumbbell gears B'I and 88 are used instead of elliptical gears, providing a lcyclic speed changer between the planet shaft and the cutter support shaft.

Obviously it makes little difference whether any cyclic connection from the planet or planets engage with a gear such as 29, directly with the lower cutter support or with'the shaft by which this cutter support is driven provided the connection be made from the planet or planets to a rotary part of the cutter train and that the connection provide a cycle of speed variation by reason of which variation of the sun gear position orof the relation between the sun gear and planet will give diierent speeds at the instants of cut for different adjustments of the sun gear or the. relation between the gears.

In operation The setting of the sun gear will correspond with the rintended length of cut and accordingly no particular setting of the sun can be considered as a zero setting. For a given length of cut the speed of the motors is set for the required speed of rotation with respect to the speed of the stock. The sun gear is then adjusted to a position in .which the speed of the cutters will correspond substantially or exactly according to the requirements with thevspeed of the runningstock. The instantaneous value of the speed at the time of cut will preferably be on that part of the cycle of speed `change at which the speed is increasing so that the cutters will clear from the advancing uncut stock and at the same time will cause each cut piece to lead the advancing stock by an amount depending upon the rate of increase in velocity of the knife after the cut.

The same process of 'fitting the number of rotations of the cutters to the length to be cut and then fitting the speed of revolution o f the cutting knives at the instant of cutting to the speed of travel of the stock is repeated for each new length of cut stock.

The character of phase changing or cyclic speed changing mechanism interposed between the planet gear and the cutter train does not afrect my broad invention but may very decidedly affect the convenience, efficiency, ruggedness and range of adjustment available.

It will be evident that the adjustment of speed for a length of cut as well as the adjustment of .cutter speed tocorrespond with thejspeed of the running stock may be arrived at wholly independently of any scales and can be made by cut and try methods. However, a scale of some character to indicate the speed 'of rotation ofthe motors or the number of turns of the cutters for any given controller or rheostat position and a scale by which in termsof length of cut or angular turn of the sun gear or any other relational factor, offers great advantage in speed of initial setting and avoidance of loss of stock during cut and try methods, leaving a ilne adjustmentonly l if necessary to cut and try methods. p

With the crank and connecting rod or pitman `connection with a rotating member of the cutting train a very high degree of speedvariation 1s attained. This makes it possible to compensate for very wide range in motor speed, matching the speed of revolution of the knives with the speed of the running stock. If the range be insufficient for the range of length'of cutgrequired or if individual users prefer not to employ the whole or a very large part of the range of'speed available, as for example because of the position on the curves of Figures 'd or 7 which would be represented by such use, the range of motor speed can be reduced by using both cutters upon the cutter support I6 for the shorter cuts and removing one of the cutter knives from this cutter support so as tochange from two cuts per rotation to one cutper rotation of this support for the longer cuts.

This would give a permissible higher minimum motor speed at all times than would be available" with uniform cutting rate per revolution.

With a higher minimum of motor speed and the same maximum of motor speed the difference between these speeds to be taken care of by variation of the instantaneous cutting speed of the knives would be much reduced, permitting either tion should not be increased, for example, in

multiples of two with corresponding reduction in essential range of cyclic speed variation.

The additional number of cutting knives as outlined in the previous paragraph gives opportunity for selectively dropping -or removing knives to reduce the range of lengths of cut which must be taken care of by differences in driving speed and which must correspondingly require adjustment by a cyclic connection between the planet and the cutting train in order to match the speed of stock.

ItY will be evident that. shift of the angular po' sition ofthe sun gear or the relation between the sun and planet causes a phase adjustment between the cyclic change of speed and the cutting knives at the time of cutting.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part oi' the benefits of my invention without copying `the structure shown, and I. therefore, claim'all such in so far as they fall within the reasonable .spirit and scope of my invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent isz- 1.*The method of operating rotary cutting mechanism, forming part of a cutting train, by a planetary gear which is revolved about a sun gear fixed in use, which consists in interposing a cyclic speed changing transmission between the planet and a rotary part of the cutting train and in angularly shifting the sun gear to a new xed position in order to cut at a speed corresponding to a new part of the speed cycle. i

2. The method of operating rotary cutting mechanism, forming part of a cutting train, from a planetary gear which is revolved about a sun gear fixed in use, which consists in revolving the planetary gear uniformly about the sun gear, in interposing a crank movement between the planet and a rotary part of the cutting. train to vary the speed of the train by added or subtracted crank movement from the speed otherwise given to it by the planet and in changing the cutting speed by angularly shifting the sun gear to shift the point in the speed cycle at which cutting takes place.

3. The method of operating rotary cutters which are part of a cutting train, which consists in driving a rotary part of the train from a crank carried by a planet gear revolving about a sun gear and in altering the angular position of the sun gear to cut at a new point in the crank operation.

4. The method of cutting stock by a rotary shear driven by a sun and planet, which consists in revolving the planet uniformly about the sun, in introducing a cyclic motion between the planet and the shear and in angularly shifting the position of the sun for variant lengths of cut.

5. The method of cutting stock while in motion by a rotary flying shear, sun, planet and cyclic speed changing mechanism between the planet and shear, which consists in rotating the shear, in cyclically moving the shear by the planet, in varying the rotary shear speed for different lengths of cut and in rotarily adjusting the sun position and setting a position of the stationff ary sun for any particular length of cut. f.

6. In the art of shearing metal stock while in motion, using a rotary flying shear having'cooperating knives moving in the direction of the stock at the time of cut, the method which consists in moving the knives rotarily and cyclically about their axes and at the time of cut increasing the knife speeds from. a speed below to a speed above the stock speed within the range of cyclic motion for all lengths of cut,'whereby the piece of stock just severed by the knives is given a lead and the knives move forward faster than the advancing stock.

7. In a rotary flying shear, a cutting train including a pair of rotary knives and gearing for intermeshing the knives, in combination with a sun, a planet uniformly revolved about the sun and means between the planet and a rotary part of the cutting train for imposing a cyclic motion on the rotary knives.

8. In a rotary flying shear, a cutting train including a pair of rotary knives and gearing for planet, means between intermeshing. the knives, in *combinationwith a normally stationary sun, a planet uniformly 'revolved about the sun,

the planet and a rotary part of the cutting train for moving the rotary knives at different speeds during different parts oi' their rotary motions, and means for angularly adjusting the sun.

9. In a rotary flying shear, a cutting train including a pair of rotary knives and gearing for the knives, a connecting rod driving a rotary. part of the train, a planetary gear, a crank arm driven by the planetary gear and driving the connecting rod, a sun gear, a planet rotor for the planet gear by which it is revolved about the sun gear as a ilxed gear and means for angularly adjusting the position of the sun gear.

10. In a rotary flying shear, a cutting train including a pair of rotary knives and gearing for the knives, a connecting rod driving a rotary part of the train, a, planetary gear, a crank arm driven by the planetary gear and driving the connecting rod, a sun gear, a planet rotor for the planet gear by which it is revolved about the sun gear as a fixed gear, means for angularly adjusting the position of the sun gear and changeable speed driving means for rotating the rotor about the sun gear.

' l1. In a rotary flying shear, a cutting train including cooperating rotary knives and intermeshing gearing between the knives, a sun gear, a planet rotor for a planet gear and a planet gear mounted thereon, means for driving the rotor to revolve the planet gear in engagement with the sun gear, cyclic speed changing connections between the planet gear and a rotary part of the cutting train and means for angularly adjusting the sun gear to vary the point upon the speed variation ycle at which cutting takes place.

12. In a rotary iiying shear, a cutting train including cooperating rotary knives and intermeshing gearing between the knives, a sun gear, a planet rotor for a planet gear and a planet gear mounted thereon, means for driving the rotor to revolve the planet gear in engagement with the sun gear, a crank arm and pin rigid with the planet gear, a cormecting rod engaging the crank pin at one end and cooperatively connected at the other end with a rotary part of the cutting train and means for angularly adjusting the sun gear about its axis and holding it at any adjusted position.

13. In a rotary flying shear, a cutting train, planetary gearing of the type having the planet revolved about a xed sun gear, cyclic speed changing connections between the planet and a rotary part of the cutting train and means for angularly relatively adjusting the sun gear and planet gear, one with respect to the other and for holding the sun in position.

14. A rotary shear having cooperating knives, a planet rotor, planet gears on the planet rotor, crank shafts mounting the planet gears, driving connections between the crank shafts and rotary shear for impressing upon said shear simultaneous movements of rotation and speed oscillation, a normally stationary angularly adjustable sun gear cooperating with the planet gears and means for operating the planet rotor.

15. In a flying shear, a main driving shaft, a sun gear surrounding the driving shaft, a planetary gear revoluble about the sun gear and driven through space by the shaft, a crank rigidly connected with the planetary gear, a pair of intermeans for driving the A aromas geared shear knife supports carrying cooperating shear knives, a connecting rod between the crank and one of the shear knife supports and means for rotarily adjusting the sun gear to alter the position of the crank with respect to the meeting position of the knives.

16. In a flying shear, cooperating rotary shear supports, knives thereon, means for rotating the supports in the direction of motion of the stock, means for giving the knives a cyclic motion about their axes of rotation, and means for shifting the phase displacement of the speed-increasing portion of the cyclic motion with respect to the time of meeting of the knives, whereby the knives at the time oi cut are in the act of speeding up from a speed below to aspeed above that o the stock to give the piece of stock just cut a lead over the advancing stock and to move the knives ahead nected to the other knife support, a plurality of connecting rods pivotally secured at one end to said first gear, a main drive shaft, a variable speed motor driving the main drive shaft, a planet rotor on the main drive shaft, a plurality of crank shafts pivotally supported by the planet rotor at spaced points, parallel to the main drive shaft and at a distance from the main drive shaft, a crank on each crank shaft connected to the other end of one of said connecting rods,v a planet gear on each crank shaft. a sun gear through which the main drive shaft passes and about which the planets revolve, a worm wheel secured to the sun gear, a worm engaging the worm wheel and a worm adjustment shaft for the worm.

19. In a rotary flying shear, a pair of cooperating rotary shear knives, a sun gear which is fixed for any given length of cut, a planet gear intermeshing with the sun gear. means for revolving the planet gear with respect to the sun gear, connections between the planet gear and the rotary knives transmitting to the knives rotary and cyclic motions, means for angularly shifting the sun gear for variant lengths of cut and an indicator for the angular position of the sun gear reading in terms of length of out.

20. The method of bringing the peripheral speed of rotary cutting knives into approximate agreement with the linear speed of the stock at the time of cutting, which consists in imparting to the rotary cutting knives a cyclic peripheral speed change and in altering the relative position in the cycle of peripheral speed change at which cutting takes place to cut at positions dii- !erent from the maximum and peripheral speeds attained by the rotary cutting knives during their rotation for the particular cut.

21. The method of cutting moving stock by rotary cutting knives, which consists in varying the revolutions per minute of the rotary cutting knives to vary the length of cut, in producing a cyclic change in the peripheral speed of the rotary cutting knives, in cutting at a position in the cycle between the position of maximum and that of minimum peripheral speed attained during the rotation for the particular cut and in altering the position of cut along the cycle between said maximum and minimum.

` GUSTAF L. FISK. 

